So, I'm still working on cycling my 5.5 gallon, and I had just planted it (I disinfected the plants beforehand.) I noticed today the water was kinda cloudy and I took out my heater to scrub the walls and it was covered in this clear slimy stuff. What is it and how can I get rid of it? (There aren't any fish in the tank yet)

The water being cloudy (if it is a white cloud) sounds like a bacteria bloom, that's very common in tanks first cycling. You can get rid of the cloud with a simple water change, it might be around a few days but it should clear up soon. As for the slime, that is most likely biofilm, also common and needed in tanks; snails eat it and it overall is just an asset to the tank. You can scrub it off but it will come back so there isn't too much use in trying to 'clean' it.

I'm planning on getting a betta and maybe a snail! And I don't need to finish cycling? I have some dwarf hair grass, anubias, and a moss ball (well, two.) I do have some nitrates and I think there are some nitrites in there too, but the color the water test comes up as is like reddish when it should be some shade of bluish/purple.

I would finish cycling with those plants. Stem plants are great for sucking up ammonia but your plants are more slow-growing. Look into wisteria, rotala, water sprite and the likes. What kind of snail?

If the plants are actively growing, you won't need to finish cycling because the plants will do it for you and the fish will provide the ammonia. Although I do suggest you get a few more plants if you want to have a nice planted tank. What kind of lighting do you have? Use any ferts?

I'm hoping for a nerite, but my LPS doesn't receive a lot of shipments of them apparently. I'll definitely look into those stem plants though! I've just started using root-tabs, and I'm going to have to change the lightbulb (it's an kind of like an old-fahioned lightbulb that give off yellow-ish light)

Also, how does one get water pH down? Mine seems to be constantly at 8.0 ppm

A nerite is a great choice! Root tabs are not being utilized by your plants. Anubias should not be buried but tied to a rock or driftwood. The moss balls also receive nutrients from the water column. I suggest investing in a bottle of Seachem Flourish. The light you have is likely an incandescent bulb and cannot support plant life. Wal-Mart carries Flourescent bulbs in the fish section (read the box, they sell incandescents for planted tanks right next to them!) for under $5. Don't worry about your pH. I keep bettas and nerites and my pH is 8.4!Posted via Mobile Device